Cutting head for a reamer

Abstract

The present invention provides a cutting head of a reamer. At least two wiping pads extend rearwardly from a cutting head forward end. At least one cutting section comprises a cutting edge that extends from the cutting head forward end to the peripheral surface. The cutting edge is formed at the intersection of a rake surface and a relief surface. The rake surface is generally tangentially directed and faces a direction of rotation. A deflecting surface is formed adjacent the rake surface and generally transverse thereto. The deflecting surface extends from a rake surface first end in a direction away from the cutting edge. The deflecting surface makes an acute axial angle with respect to the axis of rotation. A rear end of the deflecting surface joins the peripheral surface adjacent the cutting section and distal the rear end of the cutting head.

1. A cutting head ( 10 ) of a reamer having an axis of rotation (A) defining a forward-to-rear direction and comprising:
 a cutting head forward end ( 14 ), a cutting head rear end ( 16 ) distal the cutting head forward end ( 14 ) and a peripheral surface ( 18 ) therebetween, the peripheral surface ( 18 ) comprising at least two wiping pads ( 22 ) extending rearwardly from the cutting head forward end ( 14 ), the peripheral surface ( 18 ) between two adjacent wiping pads forming a peripheral section ( 58 ), and 
 at least one cutting section ( 20 ) located adjacent the cutting head forward end ( 14 ) comprising: 
 a cutting edge ( 30 ) extending from the cutting head forward end ( 14 ) in a rearward and radially outward direction to the peripheral surface ( 18 ), the cutting edge being formed at an intersection of a rake surface ( 32 ) and a relief surface ( 34 ), the rake surface ( 32 ) being generally tangentially directed, facing a direction of rotation (B) and having a rake surface first end ( 40 ) that is distal from the cutting edge ( 30 ), 
 a deflecting surface ( 38 ) adjacent the rake surface ( 32 ) and generally transverse thereto, the deflecting surface ( 38 ) extending from the rake surface first end ( 40 ) in a direction away from the cutting edge ( 30 ), wherein: 
 the deflecting surface ( 38 ) makes an acute axial angle (α) with respect to the axis of rotation (A) such that an imaginary extension of the deflecting surface ( 38 ) intersects the axis of rotation (A) at a point forward of the cutting head, and 
 a rear end ( 41 ) of the deflecting surface ( 38 ) joins the peripheral surface ( 18 ) adjacent the cutting section ( 20 ) and distal the rear end ( 16 ) of the cutting head ( 10 ). 
 
     
     
       2. The cutting head according to  claim 1 , wherein the deflecting surface ( 38 ,  138 ) joins a wiping pad ( 22 ,  122 ). 
     
     
       3. The cutting head according to  claim 1 , wherein the deflecting surface ( 38 ) is planar. 
     
     
       4. The cutting head according to  claim 1 , wherein the deflecting surface ( 38 ) is concave. 
     
     
       5. The cutting head according to  claim 1 , wherein the deflecting surface ( 38 ) makes a non-zero tangential angle (β) with respect to a line (E) perpendicular to a radially extending line (F) passing through a forward end ( 43 ) of the deflecting surface ( 38 ) as seen in a forward end view of the cutting head ( 10 ). 
     
     
       6. The cutting head according to  claim 5 , wherein the tangential angle (β) is acute and negative. 
     
     
       7. The cutting head according to  claim 1 , wherein the rake surface ( 32 ) is slanted at a negative acute axial angle (θ) with respect to the axis of rotation (A) as seen in a side view of the cutting head ( 10 ). 
     
     
       8. The cutting head according to  claim 1 , wherein the deflecting surface ( 38 ) comprises a first deflecting portion ( 42 ) that is connected to the cutting head forward end ( 14 ) and extending rearwardly therefrom and a second deflecting portion ( 44 ) that is connected to the first deflecting portion ( 42 ) and extending rearwardly therefrom. 
     
     
       9. The cutting head according to  claim 1 , wherein the cutting head ( 10 ) is detachably connected to a tool holder ( 86 ). 
     
     
       10. The cutting head according to  claim 9 , wherein the cutting head ( 10 ) is provided with a through bore ( 46 ) having a bore peripheral wall ( 48 ) extending from the cutting head forward end ( 14 ) to the cutting head rear end ( 16 ), the through bore ( 46 ) comprising an engaging arrangement ( 50 ) located on the bore peripheral wall ( 48 ), adjacent the cutting head rear end ( 16 ). 
     
     
       11. The cutting head according to  claim 1 , wherein the at least one cutting section ( 20 ) comprises a generally radially directed channel ( 52 ) located at the cutting head forward end ( 14 ), the channel ( 52 ) having channel side walls ( 54 ,  56 ) and a channel bottom wall ( 57 ) therebetween, the channel side walls ( 54 ,  56 ) extending generally in a radial direction with respect to the axis of rotation (A). 
     
     
       12. The cutting head according to  claim 1 , wherein the wiping pads ( 22 ) extend from the cutting head forward end ( 14 ) to the cutting head rear end ( 16 ). 
     
     
       13. The cutting head according to  claim 1 , wherein the peripheral section ( 58 ) is planar. 
     
     
       14. The cutting head according to  claim 1 , wherein the peripheral section ( 58 ) is concave. 
     
     
       15. The cutting head according to  claim 1 , wherein the peripheral section ( 58 ) is convex. 
     
     
       16. The cutting head according to  claim 1 , wherein:
 the peripheral section ( 58 ) is divided into a first peripheral section ( 60 ), a second peripheral section ( 66 ) and a peripheral intermediate section ( 70 ) therebetween that is spaced from the axis of rotation (A) by an intermediate distance (r) which is smaller than a cutting radius (R) by which the wiping pads are spaced from the axis of rotation (A). 
 
     
     
       17. The cutting head according to  claim 1 , wherein:
 the peripheral section ( 58 ) is divided into a first peripheral section ( 60 ), a second peripheral section ( 66 ) and a peripheral intermediate section ( 70 ) therebetween that is spaced from the axis of rotation (A) by an intermediate distance (r) which is equal to a cutting radius (R) by which the wiping pads are spaced from the axis of rotation (A). 
 
     
     
       18. The cutting head according to  claim 1 , wherein the relief surface ( 34 ) comprises a first relief surface ( 74 ) adjacent the cutting edge ( 30 ) and a second relief surface ( 76 ) tangentially extending beyond the first relief surface ( 74 ), the first relief surface ( 74 ) forming a first relief tangential angle (γ), the second relief surface ( 76 ) forming a second relief tangential angle (δ), and the second relief tangential angle (δ) is greater than the first relief tangential angle (γ) as seen in a forward end view of the cutting head ( 10 ). 
     
     
       19. The cutting head according to  claim 1 , wherein the wiping pad ( 22 ) comprises a wiping leading edge ( 24 ), a wiping trailing edge ( 26 ) peripherally behind the wiping leading edge ( 24 ), and a wiping surface ( 28 ) therebetween that lies on a cylindrical surface having a diameter no greater than a cutting head external diameter (D). 
     
     
       20. The cutting head according to  claim 19 , wherein the wiping leading edge ( 24 ) is parallel to the wiping trailing edge ( 26 ). 
     
     
       21. The cutting head according to  claim 1 , further comprising:
 a rear circular disc ( 82 ) proximate the cutting head rear end ( 16 ) and rearwardly therefrom, the rear circular disc ( 82 ) having an axis of rotation that coincides with the axis of rotation (A) of the cutting head ( 10 ), the rear circular disc ( 82 ) having a disc diameter (d) that is slightly smaller than a cutting head external diameter (D). 
 
     
     
       22. The cutting head according to  claim 1 , wherein the cutting head ( 10 ) has unitary one-piece construction and comprises sintered carbide powders. 
     
     
       23. The cutting head according to  claim 1 , wherein:
 the cutting edge ( 30 ) defines a cutting head external diameter (D); 
 the cutting head ( 10 ) comprises a rear circular disc ( 82 ) located rearwardly to the cutting head rear end ( 16 ) and having an axis of rotation that coincides with the axis of rotation (A) of the cutting head ( 10 ), and 
 the rear circular disc ( 82 ) has a disc diameter (d) that is slightly smaller than the cutting head external diameter (D). 
 
     
     
       24. The cutting head according to  claim 23 , wherein the cutting head comprises a deflecting surface ( 38 ) adjacent the rake surface ( 32 ) and generally transverse thereto, the deflecting surface ( 38 ) extending from the rake surface first end ( 40 ) in a direction away from the cutting edge ( 30 ), and wherein:
 the deflecting surface ( 38 ) makes a negative acute axial angle (α) with respect to the axis of rotation (A) such that an imaginary extension of the deflecting surface ( 38 ) intersects the axis of rotation (A) at a point forward of the cutting head, and a rear end ( 41 ) of the deflecting surface ( 38 ) joins the peripheral surface ( 18 ) adjacent the cutting section ( 20 ) and distal the rear end ( 16 ) of the cutting head ( 10 ).